power of attorney - A written instrument authorizing another (not necessarily a lawyer) to act as one's agent or attorney.  

precedent - A rule of law that is established by an appellate court in an earlier case serves as binding precedent in all subsequent similar cases.  

prejudicial evidence - Evidence which might unfairly sway the judge or jury to one side or the other. For example, photographs of a gory murder scene might inflame a jury without providing useful evidence. May be excluded in criminal cases if prejudicial effect outweighs probative value.  

prejudicial error - Synonymous with "reversible error"; an error which warrants the appellate court in reversing the judgment before it.  

preliminary hearing - A probable cause hearing which screens felony criminal cases by deciding whether there is enough evidence to warrant a trial. If the judge determines there is sufficient evidence, the defendant is "bound over" for trial. The defendant may waive this hearing.  

preliminary injunction - In civil cases when it is necessary to preserve the status quo prior to trial, the court may issue a preliminary injunction or temporary restraining order ordering a party to carry out a specified activity.  

preliminary inquiry - In Juvenile Court, an investigation and study conducted by the probation department upon receiving a referral to determine whether further action should be taken.  

premeditation - The planning of a crime preceding the commission of the act, rather than committing the crime on the spur of the moment.  

preponderance of evidence - Evidence which is (even minimally) of greater weight or more convincing than the evidence which is offered in opposition to it. This is the standard by which a plaintiff must prove his/her case in a civil suit.